package com.guapi.service;

import com.github.benmanes.caffeine.cache.CacheLoader;
import com.github.benmanes.caffeine.cache.Caffeine;
import com.github.benmanes.caffeine.cache.LoadingCache;
import com.guapi.dao.DiscussPostMapper;
import com.guapi.entity.DiscussPost;
import com.guapi.util.SensitiveFilter;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.web.util.HtmlUtils;

import javax.annotation.PostConstruct;
import java.util.List;
import java.util.concurrent.TimeUnit;

@Service
public class DiscussPostService {
    private static final Logger logger = LoggerFactory.getLogger(DiscussPostService.class);

    @Autowired
    private DiscussPostMapper discussPostMapper;

    @Autowired
    private SensitiveFilter sensitiveFilter;

    @Value("${caffeine.posts.max-size}")
    private int maxSize;

    @Value("${caffeine.posts.expire-seconds}")
    private int expireSeconds;

    //caffeine 核心接口Cache,LoadingCache,AsyncLoadingCache

    //帖子列表缓存
    private LoadingCache<String ,List<DiscussPost>> postListCache;

    //帖子总数缓存
    private LoadingCache<Integer,Integer> postRowsCache;

    @PostConstruct
    public void init(){
        //初始化帖子列表
        postListCache= Caffeine.newBuilder()
                .maximumSize(maxSize)
                .expireAfterWrite(expireSeconds, TimeUnit.SECONDS)
                .build(new CacheLoader<String, List<DiscussPost>>() {
                    @Override
                    public @Nullable List<DiscussPost> load(@NonNull String key) throws Exception {
                        if (key==null||key.length()==0){
                            throw new IllegalArgumentException("参数错误");
                        }
                        String[] params=key.split(":");
                        if (params==null||params.length!=2){
                            throw new IllegalArgumentException("参数错误");
                        }
                        int offset=Integer.valueOf(params[0]);
                        int limit=Integer.valueOf(params[1]);

                        //二级缓存：Redis-->mysql
                        return discussPostMapper.selectDiscussPosts(0,offset,limit,1);
                    }
                });
        //初始化帖子总数缓存
        postRowsCache=Caffeine.newBuilder()
                .maximumSize(maxSize)
                .expireAfterWrite(expireSeconds, TimeUnit.SECONDS)
                .build(new CacheLoader<Integer, Integer>() {
                    @Override
                    public @Nullable Integer load(@NonNull Integer key) throws Exception {
                        logger.debug("load post list from DB");
                        return discussPostMapper.selectDiscussPostRows(key);
                    }
                });
    }

    public List<DiscussPost> findDiscussPosts(int userId,int offset,int limit,int orderMode){
        if (userId == 0&&orderMode==1) {
            return postListCache.get(offset+":"+limit);
        }
        logger.debug("load post list from DB");
        return discussPostMapper.selectDiscussPosts(userId,offset,limit,orderMode);
    }

    public int findDiscussPostRows(int userId){
        if (userId==0){
            return postRowsCache.get(userId);
        }
        logger.debug("load post list from DB");
        return discussPostMapper.selectDiscussPostRows(userId);
    }

    public int addDiscussPost(DiscussPost discussPost){
        if (discussPost == null) {
            throw new IllegalArgumentException("参数不可为空");
        }

        //转义HTML标记
        discussPost.setTitle(HtmlUtils.htmlEscape(discussPost.getTitle()));
        discussPost.setContent(HtmlUtils.htmlEscape(discussPost.getContent()));
        //过滤敏感词
        discussPost.setTitle(sensitiveFilter.filter(discussPost.getTitle()));
        discussPost.setContent(sensitiveFilter.filter(discussPost.getContent()));
        return discussPostMapper.insertDiscussPost(discussPost);
    }

    public DiscussPost findDiscussPostById(int id){
        return discussPostMapper.selectDiscussPostById(id);
    }

    public int updateCommentCount(int id,int commentCount){
        return discussPostMapper.updateCommentCount(id,commentCount);
    }
    public int updateStatus(int id, int status){
        return discussPostMapper.updateStatus(id, status);
    }

    public int updateType(int id, int type){
        return discussPostMapper.updateType(id, type);
    }

    public int updateScore(int id ,double score){
        return discussPostMapper.updateScore(id, score);
    }
}
